1. Field of the Invention
The present invention generally relates to an assembly for removing or displacing waste from the inside of a closed sample container, and more particularly to a waste removal assembly used in conjunction with an automatic sampler system which provides a temporary opening in the closure of a sample container.
2. Description of the Prior Art
The prior art provides a number of automatic sampling systems. Generally, these systems receive sample containers, remove a predetermined quantity of sample from each container at a first location, and transfer the removed sample to a second location for analysis. The sample containers usually used with these systems are open-top vials or tubes transported in the system on carousels and transferred between carousels with mechanical push-arms and other similar devices.
Using open sample containers in an automatic sampling system presents a number of problems. First, the various forces which move the container through the system may cause spills and contamination. Second, open sample containers may expose an operator to any harmful substances disposed in the containers. Finally, because open containers require special care, the cost of operation increases.
One solution to these problems is to use closed containers in an automated system which can form a temporary opening in the stopper of a closed container. However, using this system presents other problems. Specifically, the sample in the container, e.g., blood serum, may splash against the side of the container and on the bottom of the container stopper in response to operator handling and/or movements of the container in the system. Some of the sample which contacts the bottom of the stopper may adhere to the stopper and may contaminate the puncture tube which provides a temporary opening through which the system conducts sampling operations.
Thus, a through the stopper sampling system must include means for removing any sample or debris from the bottom of the stopper and the surrounding area immediately before the system moves the puncture tube through the stopper. It must remove this debris quickly and efficiently; and it must do so through the stopper without removing the stopper.
The waste removal assembly of the present invention used in conjunction with a through the stopper sampling system fulfills the above requirements. It is a simple and fully automated assembly which minimizes the expense of manufacture and assembly and gives precise, uniform, and reliable performance. It allows the automated sampling system to remove waste from the bottom of the stopper and the surrounding area of each sample tube before the system performs sampling operations through the stopper.